Fix PR2090, a typo in digraph processing.

llvm-svn: 47540
diff --git a/clang/test/Lexer/digraph.cpp b/clang/test/Lexer/digraph.cpp
new file mode 100644
index 0000000..07c085a
--- /dev/null
+++ b/clang/test/Lexer/digraph.cpp
@@ -0,0 +1,15 @@
+// RUN: clang -fsyntax-only %s
+
+%:include <stdio.h>
+
+    %:ifndef BUFSIZE
+     %:define BUFSIZE  512
+    %:endif
+
+    void copy(char d<::>, const char s<::>, int len)
+    <%
+        while (len-- >= 0)
+        <%
+            d<:len:> = s<:len:>;
+        %>
+    %>